Hi Sumit,Here, the article "a" should be followed by "an" instead, because "imaginary" begins with a vowel sound. The corrected phrase should be "along an imaginary line." Also, both "toward" and "towards" are prepositions that indicate direction, and they are often interchangeable in meaning. However, there are subtle distinctions in usage depending on context and regional preferences. "Toward" is more common in American English and is generally considered the standard form in formal writing. "Towards" is more prevalent in British English and can sometimes imply a slightly more literal or physical movement.I hope this helps you, please close the ticket if your query has been resolved.

im unable to understand this answer shoudnt it be descend towards the horizon? thats the reason i marked this answer

im unable to understand this answer shoudnt it be descend towards the horizon? thats the reason i marked this answer